1. Technical Field
Aspects of this document relate generally to combination tire tread depth measurement tools and pneumatic tire pressure gauge systems for pneumatic tires, and methods for using such systems.
2. Background Art
Worn or improperly inflated tires are a large cause of automobile accidents. For example, low tire tread decreases traction in rainy or snowy conditions, increases the risk of hydroplaning, and increases the risk for tire blowouts and flats. Because of this safety risk, most states in the United States of America have defined tread depths for legally worn out tires. Furthermore, over- or under-inflated tires contribute cause dangerous conditions, including blowouts. Underinflated tires also increase tread wear. Improper tire inflation also reduces fuel efficiency. Because of these concerns, automobile operators should monitor tread depth and tire pressure regularly. However, many people are ill-equipped to do this, and they leave it up to professionals rather than taking a less expensive, more convenient do-it-yourself approach. Even more troublesome, some people are too busy or lazy to check their tread depth and tire pressure at all. Additionally, many people have farsightedness or other vision impairments, particularly elderly drivers who are often at a higher risk for exploitation by auto mechanics. These impairments, while not always so severe as to preclude driving, make it difficult to resolve the tiny markings on conventional tread depth measurement tools. For those with such impairments, the notion of using tools with tiny, indiscernible markings is frustrating. Further, professionals have a need for inexpensive, convenient tools that expedite their offered services, and some professionals also have vision problems.
Conventional tire pressure gauges are used to measure the air pressure within a tire by placing a connector on one end of the gauge over the valve of a tire. When the connector is pushed against the valve stem, the pneumatic pressure of the air in the tire forces a measurement element to extend out of the opposite end of the tire pressure gauge. A tire with greater pneumatic pressure will force the measurement element out further than a tire with less pressure. The measurement element of conventional tire pressure gauges typically includes markings or scales that relate to the pounds per square inch (PSI), kilopascals (KPA), bars, or other unit of pneumatic pressure within the tire. Tire tread depth gauges and pneumatic pressure gauges, however, are conventionally separate tools with separate parts. However, some conventional tools exist that combine the tread depth measurement with the pneumatic pressure gauge.
For example, U.S. Pat. No. 3,696,668 to Patrick discloses a combined air pressure and tread depth gauge for pneumatic tires. Here, an indicator slide is disclosed that has a pressure indicating face and a tread depth indicating face opposite the pressure indicating face. However, it is extremely difficult to read the tiny markings on the tread depth indicating face. Further, if the slide is inserted the wrong way, the markings will be even harder to see; additional movement of the device to make the markings visible after taking the measurement carries a risk that the indicator slide will inadvertently slide forward or backward, thus distorting the measurement.
U.S. Pat. No. D317,880 to Meehan discloses a particular design of a combination tire pressure and tread depth gauge. However, the tread depth markers are, again, very small and difficult to distinguish, especially for someone with farsightedness. Further, a stopper flange is shown that prevents the slide from retracting. Therefore, the tread depth would have to be marked on the slide before determining the measurement, or determined while the slide is inserted into the tread. Again, the tiny markings make this problematic as they are not readily distinguishable.